If we accept the definition of Black which we have been given—a definition which historically defined anyone with “one drop of Black blood” as Black—we ignore the existence of multiracial people. We ignore people whose experiences may be different from those experiences which have been defined as constituting the Black experience—that is, the “essentialized” Black experience. By so essentializing, we assume that the taxonomy of race proposed by nineteenth-century white supremacists—that human beings can be classified into four races and everyone fits neatly into one slot—is a valid one. On the other hand, if we do classify multiracial people as Black, the potential for group solidarity is much greater. “We are all Black,” we say. “You cannot divide us.”

America’s first black president has deliberately shied away from spurring a national discussion on race, most recently by checking only “African-American” on his U.S. census form without offering a word of explanation about his choice.

The studied silence from the bully pulpit held by President Obama has frustrated multiracial organizations, giving rise to questions about whether the president acted out of political consideration and why the son of a black man from Kenya and a white woman from Kansas would not acknowledge his mother’s heritage.

“It’s frustrating from a point that there’s a lot of multiracial people out there who see Obama doing that, knowing that he is multiracial, and they think that maybe that’s the right choice,” said Ryan Graham, the product of a mixed-race marriage whose mother founded Project Race in 1991 to push for a multiracial classification on the census form.

“But there’s a lot of people saying maybe it’s the wrong choice,” he said…

…There is no question that Mr. Obama’s decision complies with the goals of U.S. census officials; the answer to Question 9 about race is exclusively about “self-identification in which respondents choose the race or races with which they most closely identify.”

“The racial categories included in the census form generally reflect a social definition of race recognized in this country, and are not an attempt to define race biologically, anthropologically or genetically,” the Census Bureau says in its “2010 Census Constituent FAQs.”…

…But the president’s decision to check only “black” on his census form makes complete sense to Charles W. Mills, a researcher on race and a professor at Northwestern University.

“Race is a social convention. For him to claim whiteness would be rejected by the social convention of the country. The way I see it, his decision was a perfectly reasonable one, given that this is how the American rules have been,” Mr. Mills said…